JPS58155373A - Conduction testing of power-interruption-free low voltage circuit - Google Patents

Abstract

PURPOSE:To judge the conduction of a circuit detecting a voltage generated in the neutral conductor with the ground with a local panel board by operating an earth relay mounted on a secondary side wire of a main switch gear at a substration with the adjustment of a variable resistance connected to the panel board while the power source wire is connected to various earth resistances through a resistance. CONSTITUTION:In order to examine which light panel board, for example, the No.3 main switch gear 4 in a substation is connected to, first, a zero-phase current transformer 10 and an earth relay 9 is mounted to the secondary side of the main switch gear 4 and a circuit switch 7 is closed. Then, a variable resistance 11 of a local light panel board 6 is adjusted and it is observed if a voltometer 14 indicates when the value of an ammeter 12 is shifted to an integer value of the earth relay 9. When said test is implemented in the No.3 light panel board 6 connected to the main switch gear 4, the earth relay 9 operates and the voltometer 14 indicates only a drop in the voltage of, for example, a second- grade earth resistance. This makes it clear that the main switch gear 4 is connected to the No.3 light panel board 6.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention provides power sources for low-voltage circuits such as light distribution boards and power distribution boards, which are power supply sources for electric lights, power equipment, etc., from among multiple main switches in a substation. This is an uninterruptible low voltage circuit continuity test method that allows you to quickly and reliably check whether the supply is coming from any main switch.

For construction, maintenance and inspection of low-voltage power line 1 distribution boards, etc.

It is necessary to investigate from which main switch in the substation the power for the lighting distribution board and power distribution board is supplied.

Conventionally, such investigations are carried out by a team of two workers. In other words, one person opens the main switches in the substation one by one, while the other person opens them.

Stain pressure is detected using voltage detectors, testers, etc. at the on-site distribution board, and the results are communicated to those at the substation via radios, etc.

However, the propagation of radio waves between the substation, which has a normal steel structure, and the site was poor, making it difficult to transmit radio waves, making it impossible to carry out work efficiently and reliably. Especially if you try to conduct the above-mentioned investigation by yourself.
It was extremely inefficient for a single person to conduct an investigation because the person had to go back and forth between the substation and the site several times. Also during this investigation.

Since a power outage is inevitable, there are cases in which it is impossible to conduct a power outage for some machinery or equipment that is in operation, making it impossible to conduct a power outage survey.

SUMMARY OF THE INVENTION The present invention is an uninterruptible low voltage circuit continuity test method that eliminates the problems associated with power outages and allows for reliable manual work.

The principle is that the grounding relay attached to the secondary wiring of the substation main switch is operated by adjusting the variable resistance connected to the on-site distribution board! , through the a contact, the power supply side wiring connected to the main switching secondary side is connected to the class 1.3 grounding resistor through the resistor. This allows wiring on the power supply side within the substation.

It constitutes a closed circuit consisting of a resistor, a class 1.3 grounding resistor, earth, a class 2 grounding resistor, a neutral wire, and a transformer.

This is an uninterruptible continuity test method that allows you to determine the continuity of a circuit by detecting the voltage between the ground and the neutral wire that occurs on the field distribution board.

This will be explained below based on illustrated embodiments. Fig. 1 is a circuit diagram showing one form of wiring from the substation to the on-site distribution board, and Fig. 2 is a connection diagram showing one form of connection of this circuit.
FIG. 3 shows an equivalent circuit of the detection means of this circuit.

In Fig. 1, 1 and 2 supply power (three-phase transformer,
E2 is the second type grounding for transformers 1 and 2.

E7.5 indicates type 1.3 grounding within the substation. 3 and 4 are power transformers 1. A plurality of main switches 5 and 6 in the power distribution board connected to the low voltage side terminal of the lighting transformer 2 are connected to the premises electric line on the secondary side of each of the plurality of main switches 3.4 in the power distribution board. A plurality of power distribution boards and lighting distribution boards 1 and E3 are connected via power distribution boards 5. The third type grounding of the lighting distribution board 6 is shown.

In FIG. 2, among the plurality of main switches 4 and the plurality of light distribution panels 6, those of the main switchboards 3 are shown, and the two are connected via an internal electric line.

Inside the substation, 7 is an operation switch, 8 is a resistor, 10 is a zero-phase current transformer, and 9 is a grounding relay. 8 is connected to the class 1.3 grounding resistor E1.3. (If the 1st, 2nd and 3rd type grounding is common, take a separate auxiliary ground and connect it to this.) On the other hand, 11 connected to the power supply side wiring of the field light board 6 is an operation switch, 12 is a variable resistor, 13 14 is an ammeter, and 14 connected to the neutral line is a voltmeter, each connected to a second type grounding resistor of the light panel 6. In FIG. 3, when the grounding relay 9 is activated by the voltmeter 14.

An equivalent circuit for detecting the voltage applied between the neutral wire and the ground is shown.

Therefore, in order to investigate which lighting distribution board the A5 main switch 4 in a substation is connected to using one or more configurations, first, as shown in FIG.

A zero-phase current transformer 10 is installed on the secondary side of the A3 main switch 4 in the substation.
Install the grounding relay 9 and turn on the 1-circuit switch 7. (
However, if an earth leakage breaker is installed in the main switch 4 and the lighting distribution board 6, the operating current of the grounding relay shall be set to a value below the non-operation of the earth leakage breaker. ) Then, in the primary field lighting distribution board 6, the variable resistor 11
Adjust the value of the ammeter 12 to the setting value of the grounding relay 9 and observe whether the voltmeter 14 indicates it.

Even if you perform the above test on a light distribution board other than the A3 light board,
Since the grounding relay 9 is inoperative, the circuit shown in FIG. 6 cannot be formed, so the reading on the voltmeter 14 is 0 (v).

On the other hand, when the above test is carried out on the A6 light distribution board 6 to which the main switch 4 of the house 5 is connected, the grounding relay 9 operates and the circuit shown in FIG. 6 is configured, so the voltmeter 14 gives an instruction for the voltage drop of the second type grounding resistor.

Thus, it becomes clear that the A3 main switch 4 is connected to the A3 light distribution board 6. Note that 8 and above were explained using the light circuit between the light main switch and the light distribution board.

The power circuit between the power main switch and the power distribution board can also be investigated in the same way.

Note that this test method can also be applied to wiring continuity tests between each load from the on-site lighting distribution board and power distribution board.

As explained above, if this test method is applied.

Since it is an uninterruptible method, it is a lively method that allows one person to reliably conduct continuity tests on low-voltage circuits without stopping operating machinery or equipment.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing one aspect of wiring from the substation to the on-site distribution board. FIG. 2 is a circuit connection diagram according to the present invention. FIG. 3 is a circuit diagram showing one aspect of the circuit detection means according to the present invention. Equivalent circuit diagram shown 1.2: Transformer 5, 4: Main switch 5, 6: Distribution board
7: Circuit switch 8: Resistor 9: Ground relay 10:
Zero-phase current transformer 11: Operation switch 12: Variable resistor 13
: Ammeter 14: Voltmeter X: Substation Y: Internal power line
2: On-site. Patent applicant Masuo Otsuka

Claims (1)

[Claims] A grounding relay for detecting grounding is provided on the secondary side of the main switch.
A distribution board has means for operating the ground relay, and the power supply side wiring of the main switching secondary side is connected to the ground through a resistor or the like via the a contact of the ground relay. This is a continuity testing method for low-voltage circuits characterized by uninterrupted power, in which the continuity of a single circuit can be determined by detecting the voltage generated between the neutral wire and the ground at the distribution board.